Pump or not?

Hello,

I know nothing about ponds, but have always wanted one - partly in the hope that it would attract toads who would eat the slugs.

Last year I moved into a house with a small pond.  The pond has been made from a pre-formed plastic liner, with a wooden edging built around it.  It does have a couple of plants in it but not much else.  The previous owner had fish but removed these.  He told us that the pond needed a pump.  Last weekend we went to Dobbies in Edinburgh and they told us a lot about pumps and filters.

I thought I had read somewhere that it is possible to maintain a healthy ecosystem in a  pond without pumps and filters, just by proper planting, etc.  Can you tell me if this is correct?  Also I think we should remove the raised wooden edging and maybe put flatter stones around the edge to make the pond more accessible to wildlife - is this right?  Husband is prepared to do the work, but neither of us know what we are doing!  I am a keen gardener but a pond novice.

Any advice gratefully received.  I live in rural East Lothian, in close proximity to arable farmland.

Thank you.